ARTIFICIAL RETINA USING THIN FILM TRANSISTOR TECHNOLOGY

1. TECHNICAL SEMINAR
ON
“ARTIFICIAL RETINA USING THIN FILM
TRANSISTOR TECHNOLOGY”
ELECTRONICS & COMMUNICATION
1
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
By
Yadav Dankumar v.
Guided By
Prof. Niraj Tevar

2. Introduction
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Fig 1:- Retina structure
•Retina Structure
•Retinitis Pigmentosa
•Age-Related Macular Degeneration
How it works.com

3. Thin-Film Transistor
• Implanting classified into two types: Epiretinal implant and
Subretinal implant .
• Thin-Film Transistors, fabricated on transparent and flexible
substrates.
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Fig 2 Fig 3 Fig 4 How it works.com

4. Retinal Prostheses
• Retinal prosthesis replaces function of the photoreceptors and
detects light
• Signal from prosthetic detected by inner retinal cells–
generally via electrical impulses
• Chemical signals that replicate neurotransmitter function are
also being proposed
• Safe, biocompatible, effective and able to withstand the
watery, salty eye environment
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5. Epiretinal Implant
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Fig 5 How it works.com

6. Epiretinal Implant
• Advantages:-
Minimizes the amount of microelectronics implanted and
upgrades are easy to do on the wearable portion thus
avoiding future surgery
Heat can be dissipated into the vitreous humor
External control over image processing allowing for
customizability, possible better clarity
• Disadvantages:-
Difficulty attaching the implant to the fragile inner retina
Complicated processing.
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7. Subretinal Implant
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Fig 6 How it works.com

8. Subretinal Implant
• Advantages
Utilizes the surviving bipolar cells – the next step in the
pathway –Retinal processing can take place
Placing the micro photodiodes between layers on the retina
will allow for it to be held in position next to functioning
cells
Proximity with existing neurons requires less current and
leads to better resolution
• Disadvantages:
Limited space
Heat damage due to proximity of device to retinal cells
Ambient light may not be adequate to generate current in
this array
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9. Device Complications
• Long term Complications
Replacement of vitreous fluid with saline may cause
irritation or damage to retinal surface
Irritation or damage due to long term electrical stimulus,
and residual heat
Ionic interactions between retinal cells and metallic
electrodes may cause long term degradation to tissue
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10. Limitations
• Devices are not expected to produce full, clear vision.
• Allows patient to perceive basic shapes, direction of
movements, boundaries between contrasting objects.
• Subretinal:-
Not yet clear whether solar power is sufficient to create
threshold stimulus to retinal cells.
• Epiretinal:-
Head-mounted cameras do not respond to natural eye
movement
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11. • Bio-Electronic implant reduces the requirement of donor eye.
• Partial recovery of eye sight is possible.
• Effects of Retinitis Pigmentosa can be reduced.
• ARMD can be stopped from advancing.
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Application:-
Advantages:-

12. Conclusion
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•A pulse signal generator appropriate as photo recepter cells for
implementation.
•Shows the feasibility to implant the artificial retina into human
eyeballs.
Fig 7 How it works.com

13. Future scope
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Fig 8
How it works.com

14. Reference
1. Yuta Miura, Tomohisa Hachida, and Mutsumi Kimura,
Member, IEEE , “Artificial Retina Using Thin-Film
Transistors Driven by Wireless Power Supply” IEEE
SENSORS JOURNAL, VOL. 11, NO. 7, JULY 2011.
2. David C. Ng, Chris E. Williams, Penny J. Allen, Shun Bai,
Clive S. Boyd, Hamish Meffin, Mark E. Halpern, and
Efstratios Skafidas “wireless power delivery for retinal
prosthesis” , 33rd Annual International Conference of the
IEEE EMBS Boston, Massachusetts USA, August 30 -
September 3, 2011 .
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ARTIFICIAL RETINA USING THIN FILM
TRANSISTOR TECHNOLOGY